热作模具用H13和Dievar钢的热疲劳性能

Thermal fatigue properties of H13 and Dievar steels for hot-work die

对比研究了回火温度对热作模具用H13和Dievar钢热疲劳性能的影响。H13和Dievar钢经过520、580和640℃回火处理后,采用自主搭建的Uddeholm自约束疲劳试验装置分别对试样进行1000次热疲劳试验,并用热疲劳损伤因子对热疲劳损伤过程进行定量描述。结果表明,在相同回火温度下,Dievar钢具有较低的硬度和较高的冲击性能,抗疲劳性能优于H13钢。H13和Dievar钢在580℃回火处理后,碳化物尺寸分别约为10.1μm和6.3μm,H13钢碳化物含量高且尺寸大,导致韧性和抗热疲劳性能降低。

Effect of tempering temperature on thermal fatigue properties of the H13 and Dievar hot-work die steels was investigated.The Uddeholm self-constrained thermal fatigue test was conducted on the specimens tempered at 520,580 and 640℃,and the thermal fatigue damage factors were obtained to quantify the fatigue damage of the steels.The results show that the Dievar steel has a lower hardness but higher impact property than that of the H13 steel tempered at the same temperature,and possesses better thermal fatigue resistance.Tempered at 580℃,the carbide sizes of the H13 steel and Dievar steel are about 10.1μm and 6.3μm,respectively.The high carbide content and large size of the H13 steel result in the decrease of toughness and thermal fatigue resistance.